Premix burner for a gas turbine

Abstract

A premix burner is provided, with a swirl generator and a downstream mixer tube for combusting gaseous and liquid fuel which during entry of combustion air is introduced into the burner interior space of the swirl generator and/or is introduced into the burner interior of the swirl generator on a burner axis, and also with a fuel lance which is arranged on the burner axis. The premix burner, in the transition section from the swirl generator to the mixer tube, includes at least one additional feed for introducing gaseous and/or liquid premix fuel from the wall region into the burner interior space of the mixer tube.

1. A burner for premix combustion comprising a swirl generator ( 1 ) and a downstream mixer tube ( 2 ) for combusting at least one fuel ( 13 ,  39 ) which is introduced into a burner interior space ( 16 ,  17 ) of the swirl generator ( 1 ) or of the mixer tube ( 2 ), wherein in a transition section ( 6 ,  8 ,  40 ) from the swirl generator ( 1 ) to the mixer tube ( 2 ) and/or downstream of the transition section ( 6 ,  8 ,  40 ), the burner further comprises at least one additional feed ( 18 ,  19 ,  22 ) for introducing at least one additional fuel into the mixer tube ( 2 ), wherein in the transition section ( 6 ,  8 ,  40 ), in the region of, or directly downstream of, transfer passages ( 6 ) which are arranged there, at least one feed ( 19 ,  22 ) for gaseous fuel is arranged, said gaseous fuel feed introduces gaseous fuel via at least one row of discharge openings ( 21 ,  24 ), said feed introduces gaseous fuel via at least one row of discharge openings ( 21 ,  24 ), wherein at least one row of discharge openings ( 21 ,  24 ) are arranged essentially at the same level in the flow direction, said at least one row of discharge openings ( 21 ,  24 ) can be operated separately ( 20 ,  23 ), and/or are arranged in an offset manner in the flow direction and/or are formed in different sizes, and/or with regard to the injection direction are set so that the inner wall regions of the burner are not impinged upon by fuel. 
     
     
       2. The burner as claimed in  claim 1 , further comprising a fuel lance ( 15 ) which is arranged on the burner axis ( 12 ) of the burner. 
     
     
       3. The burner as claimed in  claim 2 , wherein the fuel lance ( 15 ) extends at least into the mixer tube ( 2 ). 
     
     
       4. The burner as claimed in  claim 3 , wherein the fuel lance ( 15 ) extends into the mixer tube in a region of 40-60% of a length of the mixer tube. 
     
     
       5. The burner as claimed in  claim 2 , wherein the fuel lance ( 15 ) is configured such that both liquid and gaseous fuel can be introduced into the burner interior space ( 17 ) of the mixer tube ( 2 ) via the fuel lance ( 15 ). 
     
     
       6. The burner as claimed in  claim 2 , wherein at a tip of the fuel lance ( 15 ) both liquid pilot fuel ( 281 ) and gaseous pilot fuel ( 26 ) can be introduced into the burner interior space ( 17 ) of the mixer tube ( 2 ), the liquid pilot fuel ( 281 ) can be introduced via at least one opening ( 291 ) which is generally arranged on the burner axis ( 12 ) and/or the gaseous pilot fuel ( 26 ) can be introduced via a multiplicity of radially outwardly offset openings ( 27 ) at the tip of the fuel lance ( 15 ). 
     
     
       7. The burner as claimed in  claim 2 , wherein the fuel lance ( 15 ) is configured such that liquid fuel ( 30 ,  32 ) can be introduced in the transition section ( 6 ,  8 ,  40 ) into the burner interior space ( 16 ,  17 ) in the radial direction, and different rows or groups of openings ( 31 ,  33 ), which are arranged one behind the other in the flow direction, are available along the fuel lance ( 15 ), the rows are operated separately with liquid fuel, and the openings ( 31 ,  33 ) of different rows or groups are arranged in an offset manner in the flow direction. 
     
     
       8. The burner as claimed in  claim 2 , wherein the fuel lance ( 15 ) is configured such that gaseous fuel ( 28 ) can be introduced in the transition section ( 6 ,  8 ,  40 ) into the burner interior space ( 16 ,  17 ) in the radial direction, and different rows or groups of openings ( 29 ), which are arranged one behind the other in the flow direction, are available along the fuel lance ( 15 ), the rows are operated separately with gaseous fuel, and the openings ( 29 ) of different rows or groups are arranged in an offset manner in the flow direction. 
     
     
       9. The burner as claimed in  claim 2 , wherein the fuel lance ( 15 ) comprises at least one outer tube with a coaxially arranged inner tube and/or with radially extending partitioning walls for a separately controllable feed of liquid or gaseous fuel as pilot fuel to a tip of the fuel lance ( 15 ) and/or as premix fuel for introduction in the transition section ( 6 ,  8 ,  40 ). 
     
     
       10. The burner as claimed in  claim 1 , wherein in the transition section ( 6 ,  8 ,  40 ), in the region of transfer passages ( 6 ) which are arranged there, a feed ( 18 ) for liquid fuel is arranged, wherein the liquid fuel feed introduces liquid fuel via at least one row of discharge openings ( 35 ,  37 ), wherein provision is made for at least one row of discharge openings ( 35 ,  37 ) which are arranged essentially at the same level in the flow direction, and wherein with the presence of a plurality of said rows of discharge openings ( 35 ,  37 ) can be operated separately, and/or are arranged in an offset manner in the flow direction and/or are formed in different sizes, and/or with regard to the injection direction are set so that the wall regions are not impinged upon by fuel. 
     
     
       11. The burner as claimed in  claim 10 , wherein the at least one feed ( 18 ,  19 ,  22 ) comprises at least one at least partially encompassing distribution line which is operated via a feed ( 20 ,  23 ) with fuel. 
     
     
       12. The burner as claimed in  claim 1 , wherein the swirl generator ( 1 ) comprises at least two hollow partial cone shells which are nested inside each other in the flow direction, completing a body, the cross section of the interior space which is formed by the hollow partial cone shells increases in the flow direction, the respective longitudinal symmetry axes of these partial cone shells extend in an offset manner in relation to each other in such a way that the adjacent walls of the partial cone shells in their longitudinal extent form tangential air inlet slots or passages for the inflow of combustion air into the interior space which is formed by the partial cone shells. 
     
     
       13. The burner as claimed in  claim 12 , wherein liquid fuel is introduced via a central fuel nozzle ( 5 ) and/or gaseous fuel ( 13 ) is introduced at said tangential air inlet slots. 
     
     
       14. The burner as claimed in  claim 1 , wherein the swirl generator ( 1 ) comprises at least two hollow partial shells which are nested inside each other in the flow direction, completing a body, the cross section of the interior space which is formed by the hollow partial shells extends in a cylindrical or virtually cylindrical manner in the flow direction, the respective longitudinal symmetry axes of these partial shells extend in an offset manner in relation to each other in such a way that the adjacent walls of the partial shells in a longitudinal extent form tangential air inlet slots or passages for the inflow of combustion air into the interior space which is formed by the partial shells, and the interior space has an inner body, the cross section of which reduces in the flow direction. 
     
     
       15. The burner as claimed in  claim 14 , wherein liquid fuel is introduced via a central fuel nozzle ( 5 ) and/or gaseous fuel ( 13 ) is introduced at said tangential air inlet slots. 
     
     
       16. The burner as claimed in  claim 1 , wherein in a transition section ( 40 ) between swirl generator ( 1 ) and mixer tube ( 2 ), the burner has transfer passages ( 6 ) for transferring a flow which is formed in the swirl generator ( 1 ) into the throughflow cross section of the mixer tube ( 2 ), which is connected downstream of the transfer passages. 
     
     
       17. The burner as claimed in  claim 1 , wherein the at least one feed ( 18 ,  19 ,  22 ) comprises at least one at least partially encompassing distribution line which is operated via a feed ( 20 ,  23 ) with fuel. 
     
     
       18. A method for operating a burner for premix combustion comprising a swirl generator ( 1 ) and a downstream mixer tube ( 2 ) for combusting at least one fuel ( 13 ,  39 ) which is introduced into a burner interior space ( 16 ,  17 ) of the swirl generator ( 1 ) or of the mixer tube ( 2 ), wherein in a transition section ( 6 ,  8 ,  40 ) from the swirl generator ( 1 ) to the mixer tube ( 2 ) and/or downstream of this transition section ( 6 ,  8 ,  40 ), the burner further comprises at least one additional feed ( 18 ,  19 ,  22 ) for introducing at least one additional fuel into the mixer tube ( 2 ), wherein in the transition section ( 6 ,  8 ,  40 ), in the region of, or directly downstream of, transfer passages ( 6 ) which are arranged there, at least one feed ( 19 ,  22 ) for gaseous fuel is arranged, said gaseous fuel feed introduces gaseous fuel via at least one row of discharge openings ( 21 ,  24 ), said feed introduces gaseous fuel via at least one row of discharge openings ( 21 ,  24 ), wherein at least one row of discharge openings ( 21 ,  24 ) are arranged essentially at the same level in the flow direction, said at least one row of discharge openings ( 21 ,  24 ) can be operated separately ( 20 ,  23 ), and/or are arranged in an offset manner in the flow direction and/or are formed in different sizes, and/or with regard to the injection direction are set so that the inner wall regions of the burner are not impinged upon by fuel, the method comprising:
 operating, individually and/or in combination, for a fuel staging for different operating states, various feeds ( 18 ,  19 ,  22 ,  27 ,  29 ,  291 ,  31 ,  33 ,  35 ,  37 ) for introducing liquid and/or gaseous fuel in dependence upon the load, or upon the output which is to be generated and/or upon the combustion quality or combustion stability also with regard to pollutant emission. 
 
     
     
       19. The method as claimed in  claim 18 , wherein at least two different stages for operation with gaseous and/or liquid fuel are used, using at least two feeds which are arranged one behind the other in the flow direction, or using at least one feed ( 29 ,  31 ,  33 ) in the transition section ( 40 ) via a fuel lance ( 15 ) and at least one feed ( 18 ,  19 ,  22 ) in the transition section ( 40 ) from the wall region into the burner interior space ( 17 ). 
     
     
       20. The method as claimed in  claim 19 , wherein gaseous or liquid pilot fuel is additionally introduced into the combustion airflow via a tip of the fuel lance ( 15 ). 
     
     
       21. The method as claimed in  claim 18 , wherein natural gas and/or synthesis gas and/or crude oil are used as fuel.